nested mapping fields with the same name as the parent are not searchable

gistfile1.txt

curl -XDELETE 127.0.0.1:9200/blog/
curl -XPOST 127.0.0.1:9200/blog/

# An article has a "title" field. Article has a nested mapping of comments, which has the fields "author" and "title". 
curl -XPUT 127.0.0.1:9200/blog/article/_mapping -d '
  {
    "article": {
      "properties":{
        "title": {
          "type": "string",
          "analyzed": false
        },
        "comments": {
          "type": "nested",
          "properties": {
            "title": {
              "type": "string",
              "analyzed": false
            },
            "author": {
              "type": "string",
              "analyzed": false
            }
          }
        }
      }
    }
  }'

curl -XPUT 127.0.0.1:9200/blog/article/42 -d '
  {
    "title": "red",
    "comments": [{"author": "jim", "title": "green"}]
  }'

curl -XPOST "http://localhost:9200/blog/_refresh"

# This returns results
curl -XGET 127.0.0.1:9200/blog/article/_search -d '
  {
    "query": {
      "nested": {
        "path":"comments",
        "filter": {"term":{"author":"jim"}}
      }
    }
  }'
  
# This does not return results
curl -XGET 127.0.0.1:9200/blog/article/_search -d '
  {
    "query": {
      "nested": {
        "path":"comments",
        "filter": {"term":{"title":"green"}}
      }
    }
  }'